Appendix A Default Rules for BGA Tournaments

Appendix ADefault Rules for BGA Tournaments

If the organisers of a Go tournament in Britain, recognised by the BGA,
do not specify otherwise then the Japanese rules are understood
to apply except that triple kos are treated as draws, and komi is 6
points.

If the organisers of a Go tournament in Britain, recognised by the BGA,
specify that overtime is to be used but omit to say how it is to be
implemented, then Canadian (clock-resetting) overtime should be assumed
to apply.

A.1 Komi

Black gives White 6 points komi.

A.2 Triple Ko

Triple kos and other such repeated positions count as jigo (a draw).

A.3 Overtime

Japanese professional games traditionally use the byoyomi system. When a
player has only a few minutes left the seconds are counted down, and any
move made in less that a minute does not use up any of that player's
time.

In Britain we use the overtime system instead. When a player
has used all of their main time allocation, they go into overtime.
Overtime is made up of an unlimited number of overtime periods.
When a player has used the main allocation, the ﬁrst overtime period
begins.

In each overtime period the player must play a speciﬁed number of moves
within a speciﬁed time period. Typically, the main allocation might be one
hour each, and the overtime periods for each might be ﬁve minutes in which
to play thirty stones.

A play (or move) consists in placing a stone on an intersection (or
passing) and then pressing the clock. If a player fails to make the
speciﬁed number of moves within the speciﬁed interval, they lose
immediately.

If a player plays the speciﬁed number of stones within the speciﬁed
interval, what happens next? There are various systems.

Canadian overtime

The next overtime period begins immediately. The clock is set to
the time speciﬁed for the next overtime period, and the speciﬁed
number of stones are counted out. The next overtime period
begins when the opponent next presses the clock.

Milton Keynes overtime

The player plays on freely until the current allocation of time is
consumed, for example until the ﬂag on their clock falls. Then the
clock is set to the time speciﬁed for the next overtime period, and
the speciﬁed number of stones are counted out.

(deprecated)

The player counts out the number of stones speciﬁed for the next
overtime period, and starts to play these next turn, while still
using the time remaining in the current overtime period. When
that allocation of time is consumed (that is, the ﬂag falls) the clock
is set to the next allocation of time, which begins immediately.

(strongly deprecated)

The player counts out the number of stones speciﬁed for the next
overtime period, and adds to the clock the next allocation of time.

The method preferred by the BGA is method 1, Canadian overtime.

Method 3, and particularly method 4, are deprecated by the BGA because
of the difficulty of ensuring that they are applied correctly and accurately
while at least one of the players is short of time.

With Milton Keynes overtime, the player whose clock must be reset is the
player whose move it is. With Canadian overtime, the player whose clock
must be reset is the other player. Thus with Canadian overtime, but not with
Milton Keynes overtime, the player who is thinking about her move can
continue to do so, while the other player resets the clock. This is a reason
why Canadian overtime is preferred.

Tournament organisers are free to specify any method of timekeeping
that they choose, including methods 3 and 4 above, and methods other than
overtime. However if a sufficiently eccentric method is used then
the tournament may not be eligible for inclusion in the European
ratings system. (Summary of the conditions for a tournament to be
included.)

Often, each overtime period will be identical, with the same number of
stones to be played in the same interval. For example twenty stones in ﬁve
minutes (commonly abbreviated 20/5) or thirty stones in ﬁve minutes
(30/5).

Some tournament organisers choose to specify a sequence of differing
periods (the same sequence for both players). For example 20/10, then
20/5, then 40/5, then 40/5.